// Layout helpers for each component positioning
define(function(require) {
    'use strict';

    var zrUtil = require('zrender/core/util');
    var BoundingRect = require('zrender/core/BoundingRect');
    var numberUtil = require('./number');
    var formatUtil = require('./format');
    var parsePercent = numberUtil.parsePercent;
    var each = zrUtil.each;

    var layout = {};

    /**
     * @public
     */
    var LOCATION_PARAMS = layout.LOCATION_PARAMS = [
        'left', 'right', 'top', 'bottom', 'width', 'height'
    ];

    /**
     * @public
     */
    var HV_NAMES = layout.HV_NAMES = [
        ['width', 'left', 'right'],
        ['height', 'top', 'bottom']
    ];

    function boxLayout(orient, group, gap, maxWidth, maxHeight) {
        var x = 0;
        var y = 0;

        if (maxWidth == null) {
            maxWidth = Infinity;
        }
        if (maxHeight == null) {
            maxHeight = Infinity;
        }
        var currentLineMaxSize = 0;

        group.eachChild(function (child, idx) {
            var position = child.position;
            var rect = child.getBoundingRect();
            var nextChild = group.childAt(idx + 1);
            var nextChildRect = nextChild && nextChild.getBoundingRect();
            var nextX;
            var nextY;

            if (orient === 'horizontal') {
                var moveX = rect.width + (nextChildRect ? (-nextChildRect.x + rect.x) : 0);
                nextX = x + moveX;
                // Wrap when width exceeds maxWidth or meet a `newline` group
                // FIXME compare before adding gap?
                if (nextX > maxWidth || child.newline) {
                    x = 0;
                    nextX = moveX;
                    y += currentLineMaxSize + gap;
                    currentLineMaxSize = rect.height;
                }
                else {
                    // FIXME: consider rect.y is not `0`?
                    currentLineMaxSize = Math.max(currentLineMaxSize, rect.height);
                }
            }
            else {
                var moveY = rect.height + (nextChildRect ? (-nextChildRect.y + rect.y) : 0);
                nextY = y + moveY;
                // Wrap when width exceeds maxHeight or meet a `newline` group
                if (nextY > maxHeight || child.newline) {
                    x += currentLineMaxSize + gap;
                    y = 0;
                    nextY = moveY;
                    currentLineMaxSize = rect.width;
                }
                else {
                    currentLineMaxSize = Math.max(currentLineMaxSize, rect.width);
                }
            }

            if (child.newline) {
                return;
            }

            position[0] = x;
            position[1] = y;

            orient === 'horizontal'
                ? (x = nextX + gap)
                : (y = nextY + gap);
        });
    }

    /**
     * VBox or HBox layouting
     * @param {string} orient
     * @param {module:zrender/container/Group} group
     * @param {number} gap
     * @param {number} [width=Infinity]
     * @param {number} [height=Infinity]
     */
    layout.box = boxLayout;

    /**
     * VBox layouting
     * @param {module:zrender/container/Group} group
     * @param {number} gap
     * @param {number} [width=Infinity]
     * @param {number} [height=Infinity]
     */
    layout.vbox = zrUtil.curry(boxLayout, 'vertical');

    /**
     * HBox layouting
     * @param {module:zrender/container/Group} group
     * @param {number} gap
     * @param {number} [width=Infinity]
     * @param {number} [height=Infinity]
     */
    layout.hbox = zrUtil.curry(boxLayout, 'horizontal');

    /**
     * If x or x2 is not specified or 'center' 'left' 'right',
     * the width would be as long as possible.
     * If y or y2 is not specified or 'middle' 'top' 'bottom',
     * the height would be as long as possible.
     *
     * @param {Object} positionInfo
     * @param {number|string} [positionInfo.x]
     * @param {number|string} [positionInfo.y]
     * @param {number|string} [positionInfo.x2]
     * @param {number|string} [positionInfo.y2]
     * @param {Object} containerRect {width, height}
     * @param {string|number} margin
     * @return {Object} {width, height}
     */
    layout.getAvailableSize = function (positionInfo, containerRect, margin) {
        var containerWidth = containerRect.width;
        var containerHeight = containerRect.height;

        var x = parsePercent(positionInfo.x, containerWidth);
        var y = parsePercent(positionInfo.y, containerHeight);
        var x2 = parsePercent(positionInfo.x2, containerWidth);
        var y2 = parsePercent(positionInfo.y2, containerHeight);

        (isNaN(x) || isNaN(parseFloat(positionInfo.x))) && (x = 0);
        (isNaN(x2) || isNaN(parseFloat(positionInfo.x2))) && (x2 = containerWidth);
        (isNaN(y) || isNaN(parseFloat(positionInfo.y))) && (y = 0);
        (isNaN(y2) || isNaN(parseFloat(positionInfo.y2))) && (y2 = containerHeight);

        margin = formatUtil.normalizeCssArray(margin || 0);

        return {
            width: Math.max(x2 - x - margin[1] - margin[3], 0),
            height: Math.max(y2 - y - margin[0] - margin[2], 0)
        };
    };

    /**
     * Parse position info.
     *
     * @param {Object} positionInfo
     * @param {number|string} [positionInfo.left]
     * @param {number|string} [positionInfo.top]
     * @param {number|string} [positionInfo.right]
     * @param {number|string} [positionInfo.bottom]
     * @param {number|string} [positionInfo.width]
     * @param {number|string} [positionInfo.height]
     * @param {number|string} [positionInfo.aspect] Aspect is width / height
     * @param {Object} containerRect
     * @param {string|number} [margin]
     *
     * @return {module:zrender/core/BoundingRect}
     */
    layout.getLayoutRect = function (
        positionInfo, containerRect, margin
    ) {
        margin = formatUtil.normalizeCssArray(margin || 0);

        var containerWidth = containerRect.width;
        var containerHeight = containerRect.height;

        var left = parsePercent(positionInfo.left, containerWidth);
        var top = parsePercent(positionInfo.top, containerHeight);
        var right = parsePercent(positionInfo.right, containerWidth);
        var bottom = parsePercent(positionInfo.bottom, containerHeight);
        var width = parsePercent(positionInfo.width, containerWidth);
        var height = parsePercent(positionInfo.height, containerHeight);

        var verticalMargin = margin[2] + margin[0];
        var horizontalMargin = margin[1] + margin[3];
        var aspect = positionInfo.aspect;

        // If width is not specified, calculate width from left and right
        if (isNaN(width)) {
            width = containerWidth - right - horizontalMargin - left;
        }
        if (isNaN(height)) {
            height = containerHeight - bottom - verticalMargin - top;
        }

        if (aspect != null) {
            // If width and height are not given
            // 1. Graph should not exceeds the container
            // 2. Aspect must be keeped
            // 3. Graph should take the space as more as possible
            // FIXME
            // Margin is not considered, because there is no case that both
            // using margin and aspect so far.
            if (isNaN(width) && isNaN(height)) {
                if (aspect > containerWidth / containerHeight) {
                    width = containerWidth * 0.8;
                }
                else {
                    height = containerHeight * 0.8;
                }
            }

            // Calculate width or height with given aspect
            if (isNaN(width)) {
                width = aspect * height;
            }
            if (isNaN(height)) {
                height = width / aspect;
            }
        }

        // If left is not specified, calculate left from right and width
        if (isNaN(left)) {
            left = containerWidth - right - width - horizontalMargin;
        }
        if (isNaN(top)) {
            top = containerHeight - bottom - height - verticalMargin;
        }

        // Align left and top
        switch (positionInfo.left || positionInfo.right) {
            case 'center':
                left = containerWidth / 2 - width / 2 - margin[3];
                break;
            case 'right':
                left = containerWidth - width - horizontalMargin;
                break;
        }
        switch (positionInfo.top || positionInfo.bottom) {
            case 'middle':
            case 'center':
                top = containerHeight / 2 - height / 2 - margin[0];
                break;
            case 'bottom':
                top = containerHeight - height - verticalMargin;
                break;
        }
        // If something is wrong and left, top, width, height are calculated as NaN
        left = left || 0;
        top = top || 0;
        if (isNaN(width)) {
            // Width may be NaN if only one value is given except width
            width = containerWidth - horizontalMargin - left - (right || 0);
        }
        if (isNaN(height)) {
            // Height may be NaN if only one value is given except height
            height = containerHeight - verticalMargin - top - (bottom || 0);
        }

        var rect = new BoundingRect(left + margin[3], top + margin[0], width, height);
        rect.margin = margin;
        return rect;
    };


    /**
     * Position a zr element in viewport
     *  Group position is specified by either
     *  {left, top}, {right, bottom}
     *  If all properties exists, right and bottom will be igonred.
     *
     * Logic:
     *     1. Scale (against origin point in parent coord)
     *     2. Rotate (against origin point in parent coord)
     *     3. Traslate (with el.position by this method)
     * So this method only fixes the last step 'Traslate', which does not affect
     * scaling and rotating.
     *
     * If be called repeatly with the same input el, the same result will be gotten.
     *
     * @param {module:zrender/Element} el Should have `getBoundingRect` method.
     * @param {Object} positionInfo
     * @param {number|string} [positionInfo.left]
     * @param {number|string} [positionInfo.top]
     * @param {number|string} [positionInfo.right]
     * @param {number|string} [positionInfo.bottom]
     * @param {number|string} [positionInfo.width] Only for opt.boundingModel: 'raw'
     * @param {number|string} [positionInfo.height] Only for opt.boundingModel: 'raw'
     * @param {Object} containerRect
     * @param {string|number} margin
     * @param {Object} [opt]
     * @param {Array.<number>} [opt.hv=[1,1]] Only horizontal or only vertical.
     * @param {Array.<number>} [opt.boundingMode='all']
     *        Specify how to calculate boundingRect when locating.
     *        'all': Position the boundingRect that is transformed and uioned
     *               both itself and its descendants.
     *               This mode simplies confine the elements in the bounding
     *               of their container (e.g., using 'right: 0').
     *        'raw': Position the boundingRect that is not transformed and only itself.
     *               This mode is useful when you want a element can overflow its
     *               container. (Consider a rotated circle needs to be located in a corner.)
     *               In this mode positionInfo.width/height can only be number.
     */
    layout.positionElement = function (el, positionInfo, containerRect, margin, opt) {
        var h = !opt || !opt.hv || opt.hv[0];
        var v = !opt || !opt.hv || opt.hv[1];
        var boundingMode = opt && opt.boundingMode || 'all';

        if (!h && !v) {
            return;
        }

        var rect;
        if (boundingMode === 'raw') {
            rect = el.type === 'group'
                ? new BoundingRect(0, 0, +positionInfo.width || 0, +positionInfo.height || 0)
                : el.getBoundingRect();
        }
        else {
            rect = el.getBoundingRect();
            if (el.needLocalTransform()) {
                var transform = el.getLocalTransform();
                // Notice: raw rect may be inner object of el,
                // which should not be modified.
                rect = rect.clone();
                rect.applyTransform(transform);
            }
        }

        // The real width and height can not be specified but calculated by the given el.
        positionInfo = layout.getLayoutRect(
            zrUtil.defaults(
                {width: rect.width, height: rect.height},
                positionInfo
            ),
            containerRect,
            margin
        );

        // Because 'tranlate' is the last step in transform
        // (see zrender/core/Transformable#getLocalTransfrom),
        // we can just only modify el.position to get final result.
        var elPos = el.position;
        var dx = h ? positionInfo.x - rect.x : 0;
        var dy = v ? positionInfo.y - rect.y : 0;

        el.attr('position', boundingMode === 'raw' ? [dx, dy] : [elPos[0] + dx, elPos[1] + dy]);
    };

    /**
     * @param {Object} option Contains some of the properties in HV_NAMES.
     * @param {number} hvIdx 0: horizontal; 1: vertical.
     */
    layout.sizeCalculable = function (option, hvIdx) {
        return option[HV_NAMES[hvIdx][0]] != null
            || (option[HV_NAMES[hvIdx][1]] != null && option[HV_NAMES[hvIdx][2]] != null);
    };

    /**
     * Consider Case:
     * When defulat option has {left: 0, width: 100}, and we set {right: 0}
     * through setOption or media query, using normal zrUtil.merge will cause
     * {right: 0} does not take effect.
     *
     * @example
     * ComponentModel.extend({
     *     init: function () {
     *         ...
     *         var inputPositionParams = layout.getLayoutParams(option);
     *         this.mergeOption(inputPositionParams);
     *     },
     *     mergeOption: function (newOption) {
     *         newOption && zrUtil.merge(thisOption, newOption, true);
     *         layout.mergeLayoutParam(thisOption, newOption);
     *     }
     * });
     *
     * @param {Object} targetOption
     * @param {Object} newOption
     * @param {Object|string} [opt]
     * @param {boolean|Array.<boolean>} [opt.ignoreSize=false] Used for the components
     *  that width (or height) should not be calculated by left and right (or top and bottom).
     */
    layout.mergeLayoutParam = function (targetOption, newOption, opt) {
        !zrUtil.isObject(opt) && (opt = {});

        var ignoreSize = opt.ignoreSize;
        !zrUtil.isArray(ignoreSize) && (ignoreSize = [ignoreSize, ignoreSize]);

        var hResult = merge(HV_NAMES[0], 0);
        var vResult = merge(HV_NAMES[1], 1);

        copy(HV_NAMES[0], targetOption, hResult);
        copy(HV_NAMES[1], targetOption, vResult);

        function merge(names, hvIdx) {
            var newParams = {};
            var newValueCount = 0;
            var merged = {};
            var mergedValueCount = 0;
            var enoughParamNumber = 2;

            each(names, function (name) {
                merged[name] = targetOption[name];
            });
            each(names, function (name) {
                // Consider case: newOption.width is null, which is
                // set by user for removing width setting.
                hasProp(newOption, name) && (newParams[name] = merged[name] = newOption[name]);
                hasValue(newParams, name) && newValueCount++;
                hasValue(merged, name) && mergedValueCount++;
            });

            if (ignoreSize[hvIdx]) {
                // Only one of left/right is premitted to exist.
                if (hasValue(newOption, names[1])) {
                    merged[names[2]] = null;
                }
                else if (hasValue(newOption, names[2])) {
                    merged[names[1]] = null;
                }
                return merged;
            }

            // Case: newOption: {width: ..., right: ...},
            // or targetOption: {right: ...} and newOption: {width: ...},
            // There is no conflict when merged only has params count
            // little than enoughParamNumber.
            if (mergedValueCount === enoughParamNumber || !newValueCount) {
                return merged;
            }
            // Case: newOption: {width: ..., right: ...},
            // Than we can make sure user only want those two, and ignore
            // all origin params in targetOption.
            else if (newValueCount >= enoughParamNumber) {
                return newParams;
            }
            else {
                // Chose another param from targetOption by priority.
                for (var i = 0; i < names.length; i++) {
                    var name = names[i];
                    if (!hasProp(newParams, name) && hasProp(targetOption, name)) {
                        newParams[name] = targetOption[name];
                        break;
                    }
                }
                return newParams;
            }
        }

        function hasProp(obj, name) {
            return obj.hasOwnProperty(name);
        }

        function hasValue(obj, name) {
            return obj[name] != null && obj[name] !== 'auto';
        }

        function copy(names, target, source) {
            each(names, function (name) {
                target[name] = source[name];
            });
        }
    };

    /**
     * Retrieve 'left', 'right', 'top', 'bottom', 'width', 'height' from object.
     * @param {Object} source
     * @return {Object} Result contains those props.
     */
    layout.getLayoutParams = function (source) {
        return layout.copyLayoutParams({}, source);
    };

    /**
     * Retrieve 'left', 'right', 'top', 'bottom', 'width', 'height' from object.
     * @param {Object} source
     * @return {Object} Result contains those props.
     */
    layout.copyLayoutParams = function (target, source) {
        source && target && each(LOCATION_PARAMS, function (name) {
            source.hasOwnProperty(name) && (target[name] = source[name]);
        });
        return target;
    };

    return layout;
});
